The aim of this predoctoral training program in Genetics and Cell Biology is to train scientists to conduct research and prepare for careers in modern molecular genetics and cell biology and, in general, in the biomedical sciences. This program represents the merger of two existing successful training programs, "Genetics of Prokaryotic and Eukaryotic Organisms" with "Cell and Molecular Biology," which recognizes how they have operated to a considerable extent in the past. The new training program will bring together individuals who are studying central problems in genetics and cell biology, including regulation of the cell division cycle, control of DNA distribution in mitotic and meiotic cells, protein trafficking, and cytoskeletal organization using the tools of genetics and biochemistry. These studies exploit a wide range of systems, including bacteria, yeast, nematodes, zebrafish, and humans. The goals of the program are accomplished through coursework and other activities in genetics and cell biology and related areas and through the student's research. The features of our training program that are especially attractive to incoming students are (a) a large number of active, excellent laboratories from which students can choose for their thesis research, (b) a laboratory rotation system, which provides meaningful research experience in different laboratories, (c) an excellent set of courses that enables students with little prior training in genetics and cell biology to acquire a solid foundation in these areas, (d) tutorial training with faculty on how to present a seminar, (e) a highly collegial and interactive atmosphere at UCSF, (f) a high faculty to student ratio, and (g) an awareness that training graduate students is important to the UCSF faculty.